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in search of CD transport that'll accept external clock

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I want to build my own DSP+DAC portion of the signal chain, and need to start with a transport that'll lock to an external clock. I suppose I can buy something from Wadia, but they don't necessarily provide technical details for me hooking up non-Wadia gear to their transports.
I can very well do the hardware and software part: programming the DSP, assembling the board, etc.
I want to feed the digital audio into a DSP, likely Motorola's 56800 series (their DSP56F827 maybe?), run it through digital filters, and send it to six DACs: three per channel, one for each frequency band per channel. This then will go to six channels of power amps with three amps located at the base of each MG20.1 speakers that'll have each driver connected directly to an amp with no analog crossover.
If anyone knows of a ready-made board that'll do the DSP+DAC portion as well, with me supplying the software, then I would consider buying that too. I'll likely go with Crystal's latest CS4397.
Here are some relevant links:
http://www.cirrus.com/design/products/overview/index.cfm?DivisionID=3&SubdivisionID=8&ProductID=34
http://e-www.motorola.com/webapp/sps/site/taxonomy.jsp?nodeId=01M938563108817

Follow Ups:

Not quite sure if this is what you want, but have a look... - orejones 08:52:51 11/26/01 (0)
...at http://www.lcaudio.com/dacdrev.htm : they have some instructions on how to do it.
Luck, and regards
BF
I don't buy it... - Rbroer 01:16:26 11/26/01 (0)
If you really know how to design your own DSP hardware with 6 DAC's,
modifying an existing cd player for locking or using an external clock is child's play.
So, are you really serious or just wanna impress others; I don't buy it...
Re: in search of CD transport that'll accept external clock - dwk 15:27:08 11/25/01 (1)
Well, the idea of DSP xovers comes up relatively frequently. I'd suggest doing a search in the archives, and possibly checking out the hifi_dsp group on Yahoo groups. There's lots of information and brainstorming around, though no complete solutions.
Anyway, I'm rather puzzled by your question. Of all the issues you're facing in attempting a dsp xover project, I don't see how a transport that takes an external clock enters into things. Any spdif transport would be perfectly suited to this task. Sure, locking things to a single master clock is better, but why approach it by running an external clock into the transport?? Why not use the transport master clock to run the whole system, and simply ensure that it's a good clock? Where are you planning to get the external master clock to run the transport anyway?
If you're set on this idea, look into the industrial/pro audio circles. Pro studio gear is much more likely to be set up to slave to an external word clock input than any conventional hi-fi unit. There will also be standalone clock generators, which might be of interest.
As to the DSP side of things, the short answer is that there is nothing off the shelf that does what you want. The Motorola DSP 56362 evm came close, but is no longer available. There are some industrial SHARC development packages that you could probably make work, but they're big bucks. Whatever you decide, I'd _strongly_ recommend prototyping your filters before even thinking of designing custom hardware, though. A single motorola DSP is very likely inadequate for a good 3-way xover that takes full advantage of DSP techniques. If you develop the hardware before you know how much computation your solution needs, it would be an expensive lesson.

I'm doing basically what you describe, and am using a high-end semi-pro multichannel soundcard and a PC for the prototype. A 1+GHz Athlon has more cpu power than virtually any common DSP chip, and the PC environment offers much better facilities for filter modelling etc. I'd seriously suggest approching the problem this way, and then using the results to guide your hardware ideas.
- Re: in search of CD transport that'll accept external clock - Kondrat_K._Michelson 04:02:39 11/27/01 (0)
  Hi!
  > ... but why approach it by running an external clock into the transport?? Why not use the transport master clock to run the whole system, and simply ensure that it's a good clock?
  ---- Modification anyway, transport or DAC. In your approach, the shaman's dances around the digital cables will be continued. Well, some people like it.
  > Where are you planning to get the external master clock to run the transport anyway?
  ---- Ahy of TCXO manufacrurers has a good clock gen for this task. Just about $150 and low jitter TCXO in your pocket. Or, take a LC-Audio's XO-Clock, the same price.
  > If you're set on this idea, look into the industrial/pro audio circles. Pro studio gear is much more likely to be set up to slave to an external word clock input than any conventional hi-fi unit.
  ---- Right. Studer-ReVox and other have a fine CD player/Transport with external sync input.
  BR, Sergey.
  P.S. It's not a problem to modify any conventional CD player to get Ext. Sync. input.
Re: in search of CD transport that'll accept external clock - Peter 14:51:24 11/23/01 (0)
Nice ideas, keep posting!
/Peter

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